Halappanavar is a Senior Research Scientist in the Advanced Computing, Mathematics, and Data Division at the Pacific Northwest National Laboratory. He is a member of the Data Sciences Group and lead the Data Analytics team. His research interests broadly include parallel graph algorithms, data intensive computing, scientific computing, high-performance computing, and machine learning. He is also an adjunct faculty member in the department of computer science at the Old Dominion University, and formerly with the department of computer science at the Washington State University. Halappanavar is the PI of the recently awarded ECP Exagraph Codesign Center.